Research And Implementation Of An Network MPEG-1 Layer Ⅲ Audio Player Based On ARM9 Platform

MP3 is a high-quality music compression standard. The data quantity compressed by MP3 can reduce to 1/12 with little loss of sound quality. MP3 music has achieved transmission on the network because of its small data quantity and high-quality playing effect. Network MP3 system can abroadly apply to the field of guest room's music system of high level hotel, long-distance autobus, passenger trains and 3G mobile telephone. With network MP3 system ceaselessly developing, network MP3 system more and more applys to consumption fields and brings economy benefit and society benefit.An network MP3 player is designed and implemented in the ARM9 hardware platform in this thesis. The network MP3 player is developed with Trolltech's Qt programming languages. Network class of Qt is used to write network download module. The high-quality open source MPEG audio decoder library MAD is applied to decode MP3 files and generate PCM data. PCM data is processed by OSS audio driver program to realize playing downloaded MP3 audio files in local and network.The main contributions of this thesis includes as follows:(1) Introduce in detail the audio compression technology and relative knowledge of embedded system, Analyze MP3 encoding and decoding principle and choose the MP3 decoding library according to the feature of ARM9, which enables it to decode MP3 audio files with high efficiency.(2) The cross-compiled environment needed by the development of network MP3 player is established and the hardware development platform is put up on the host computer.(3) Research on the features of OSS audio driver and program the audio driver in accordance with the selected hardware.(4) The transplant of desktop system Qtopia and Network MP3 Player is completed on the ARM9 hardware platform.(5) In the top code level, C++ which is in line with Qt characteristics is used to design the user interface for the player in design of Network MP3 Player's software. Users can operate the touch screen to download, choose, play, pause and adjust volume of music files.